Hello- I don't think this problem will go away.
Rabbits shouldn't be left for longer than 12-24 hours of not eating. Try vegetable baby food syringed in so you know she is getting some nutrients. When they stop eating their guts stop working and they can die very quickly. I'm very worried she hasn't passed any faeces- she may be constipated or it just may be the fact that there isn't any food going through her.
The reason she isn't eating needs to be rectified, it could be her teeth- rabbits are prone to the molars- back teeth overgrowing and forming needlelike spikes on them. This makes it too painful for them to eat solids she would need sedation and the teeth would need clipping and filing down. Again it may be constipation and is backed up and doesn't want to eat. There may be a tumor or under-lying illness thats stopping her from wanting to eat. She urgently needs veterinary treatment- I would think she is only alive because you have been giving her water and so on. Don't give her juice and yogurt any more- as I said a vegetable baby food will be more nutritious but not enough long term. See a vet today.
Let me know the outcome.
Did he look at her teeth? What were the x-rays of?
Does she seem hungry when your giving her the juice?
Do you know if he examined the back teeth? He would need a tool to check these - it just sounds like its his back teeth, any problem that stops him eating would be because he didn't feel like eating. The fact he seems hungry would indicate something is stopping him eating. Can you get some baby food to feed him?
The vet should have given you some powdered feed. Do you know if the vet specialises in rabbits?